Generally, a camera module design has one camera (sensor) while, on the other hand, requirements on height, resolution, and image quality of the camera module are increasing high. It is often difficult for a single camera module to meet the requirements. If it is required to increase the resolution of a camera without increasing the module height of the camera module, the single pixel size will become smaller and the image quality will be distorted, such as with severe noise. “Single-pixel size” refers to the size of each pixel. Larger pixel can result in better photosensitive as well as less color noise. The module height of the camera module may need to be increased in order to maintain the image quality, and this will greatly reduce the user experience. For example, for a camera with the resolution of 8 M (megabytes), the module height needs to be 5 mm or more. With increasing resolution, a camera module with 13 M or higher resolution may need more module height. However, coordination between resolution, image quality, and module height of the camera module can be difficult to be achieved. For a camera module adopting dual camera design, it has only a certain improvement in the resolution while the image quality is still not improved.